Patent GB-840406-A (GB)
Title: A process for the production of readily soluble mixtures of alkali metal alkyl benzene sulphonates
IPC: C07C303/32
Filed: 1958-02-13
Abstract: Alkali-metal alkylbenzene sulphonate mixtures containing (a) sulphonates prepared from the products of the alkylation of benzene with polymers of propylene consisting mainly of molecules of four units; and (b) sulphonates prepared from monoalkyl benzenes in which at least 90% of the benzene nuclei are bound to unbranched alkyl radicals which comprise at least two different kinds of alkyl radicals each containing different numbers of carbon atoms but having not less than 10 nor more than 15 carbon atoms per alkyl radical, such radicals preferably being the four successive members having C10-13 or C12-15 alkyl groups, and monoalkylbenzenes being obtained by the alkylation of benzene with olefins formed in cracking liquid, semi-solid, or solid paraffins, are prepared by mixing the two species at any appropriate stage of preparation, e.g. by preparing mixed alkylates, by sulphonating a mixture of alkylates prepared separately, by neutralizing a mixture of sulphonic acids prepared separately, or by only mixing after the final sulphonates have been obtained separately.  Components (a) and (b) are preferably present in the weight ratio 1 : 3 to 3 : 1.  The alkylations are carried out in the presence of a catalyst such as hydrofluoric acid, either anhydrous or in solution, sulphuric acid, oleum, aluminium chloride or activated clay, the molar ratio of benzene to olefins being generally 2-20.  The sulphonation may be achieved with oleum, chlorsulphonic acid, or gaseous sulphur trioxide in sulphur dioxide, nitrogen or air.  In an example, benzene is separately alkylated at 5 DEG  C. in the presence of excess sulphuric acid with three different olefin mixtures, one being a tetrapropylene polymer and the others being mixtures containing 10-13 and 12-15 carbon atoms respectively. After settling, the upper layer is separated and refluxed with sodium hydroxide and isopropanol, after which the hydrocarbon layer is washed with salt solution and unchanged benzene distilled off.  The alkylbenzenes obtained are mixed with oleum and the temperature maintained at 25 DEG  C., after which the mixtures are diluted, the sulphonic acids separated and then neutralized with sodium hydroxide. The compositions containing alkylbenzene sulphonates of types (a) and (b) above are then compounded.  Specifications 702,013 and 749,737 are referred to.ALSO:Mixtures of alkali-metal alkylbenzene sulphonates are prepared by forming a mixture of (a) sulphonates prepared from the products of the alkylation of benzene with polymers of propylene consisting mainly of molecules of four units, and (b) sulphonates prepared from monoalkylbenzenes in which at least 90% of the benzene nuclei are bound to unbranched alkyl radicals which comprise at least two different kinds of alkyl radicals each containing different numbers of carbon atoms, but each containing not less than 10 and not more than 15 carbon atoms per alkyl radical, the monoalkylbenzenes being obtained by the alkylation of benzene with olefins formed in cracking liquid, semi-solid or solid paraffins. Components (a) and (b) are preferably present in a weight ratio of 1 : 3 to 3 : 1, and both (a) and (b) may be prepared independently and then mixed or they may be prepared by mixing at any appropriate stage, e.g. by preparing mixed alkylates, by sulphonating a mixture of alkylates prepared separately, or by neutralizing a mixture of sulphonic acids prepared separately.  In a preferred embodiment, (b) is prepared from alkylbenzenes containing as the alkyl groups four different radicals of successive numbers of carbon atoms, especially C10-13 or C12-15 alkyl groups.  The compositions may also contain other surface-active agents (none specified), alkali-metal pyro- or poly-phosphates, silicates, carbonates, sulphates or borates, carboxymethyl cellulose and other soluble derivatives of cellulose and starch, persulphates, perborates, percarbonates, optical bleach, and foam-forming and -stabilizing substances.  Specifications 702,013 and 749,737 are referred to.